Active energy-ray-curable resin composition, ink jet head having ink path wall formed by use of the composition, process for preparing the head, and ink jet apparatus provided with the head

Abstract

An active energy-ray-curable resin composition of a cation-polymerizable type for forming a wall of flow path of an ink jet head comprises 50 to 98.5% by weight of an aromatic epoxy resin having a molecular weight of not less than 300, 1 to 10% by weight of a silane coupling agent, and 0.5 to 5% by weight of an active catalyst.

What is claimed is: 
     
       1. A process for preparing an ink jet head, comprising the steps of: (a) forming a solid layer from a positive-type photosensitive resin at a position for forming a flow path communicating with an ejection opening for ejecting ink on a substrate, said substrate being provided with an energy generating member for generating energy to be utilized for ejecting ink from the ejection opening so as to correspond to the path;   (b) applying, at another position on the substrate where the solid layer is not formed, an active energy-ray-curable resin composition which is cationic-polymerizable comprising (i) 65 to 98.5% by weight of an aromatic epoxy resin having a molecular weight of not less than 300,   (ii) 1 to 10% by weight of a epoxy-functional silane coupling agent substantially free of amino, and thiol functional groups, and   (iii) 0.5 to 5% by weight of a photosensitized cationic polymerization initiator;     (c) curing the active energy-ray-curable resin composition by exposure to an active energy ray; and   (d) removing the solid layer to form the flow path.   
     
     
       2. The process for producing an ink jet head of claim 1, wherein the aromatic epoxy resin has at least two epoxy groups, and has no nitrogen atom. 
     
     
       3. The process for producing an ink jet head of claim 1, wherein the photosensitized cationic polymerization initiator is one or more compounds selected from the group consisting of aromatic onium salts, iron-arena complex, silanolaluminum complex, sulfonic acid ester dialkyl-4-hydroxyphenylsulfonium salts and dialkylphenacylsulfonium salts. 
     
     
       4. The process for producing an ink jet head of claim 1, wherein the composition has a static viscosity at 25° C. of from 1,000 cps to 100,000 cps. 
     
     
       5. The process for producing an ink jet head of claim 1, wherein the energy generating member is an electrothermal transducer for generating heat energy as the energy. 
     
     
       6. The process for producing an ink jet head of claim 1, wherein the energy generating member is a piezoelectric element. 
     
     
       7. An ink jet head produced by a process comprising the steps of: (a) forming a solid layer from a positive-type photosensitive resin at a position for forming a flow path communicating with an ejection opening for ejecting ink on a substrate, said substrate being provided with an energy generating member for generating energy to be utilized for ejecting ink from the ejection opening so as to correspond to the path;   (b) applying, at another position on the substrate where the solid layer is not formed, an active energy-ray-curable resin composition which is cationic-polymerizable comprising (i) 65 to 98.5% by weight of an aromatic epoxy resin having a molecular weight of not less than 300,   (ii) 1 to 10% by weight of a epoxy-functional silane coupling agent substantially free of amino and thiol functional groups, and   (iii) 0.5 to 5% by weight of an a photosensitized cationic polymerization initiator;     (c) curing the active energy-ray-curable resin composition by exposure to an active energy ray; and   (d) removing the solid layer to form the flow path.   
     
     
       8. An ink jet apparatus comprising an ink jet head and a power source switch, wherein said ink jet head is produced by the process comprising the steps of: (a) forming a solid layer from a positive-type photosensitive resin at a position for forming a flow path communicating with an ejection opening for ejecting ink on a substrate, said substrate being provided with an energy generating member for generating energy to be utilized for ejecting ink from the ejection opening so as to correspond to the path;   (b) applying, at another position on the substrate where the solid layer is not formed, an active energy-ray-curable resin composition which is cationic-polymerizable comprising (i) 65 to 98.5% by weight of an aromatic epoxy resin having a molecular weight of not less than 300,   (ii) 1 to 10% by weight of a epoxy-functional silane coupling agent substantially free of amino, and thiol functional groups, and   (iii) 0.5 to 5% by weight of a photosensitized cationic polymerization initiator;     (c) curing the active energy-ray-curable resin composition by exposure to an active energy ray; and   (d) removing the solid layer to form the flow path.   
     
     
       9. A process of using an active energy-ray-curable resin composition which is cationic polymerization, said composition comprising: (i) 65 to 98.5% by weight of an aromatic epoxy resin having a molecular weight of not less than 300,   (ii) 1 to 10% by weight of a epoxy-functional silane coupling agent substantially free of amino and thiol functional groups, and   (iii) 0.5 to 5% by weight of a photosensitized cationic polymerization initiator; to prepare an ink jet head, said process comprising the steps of:     (a) forming a solid layer from a positive-type photosensitive resin at a position for forming a flow path communicating with an ejection opening for ejecting ink on a substrate, said substrate being provided with an energy generating member for generating energy to be utilized for ejecting ink from the ejection opening so as to correspond to the path;   (b) applying, at another position on the substrate where the solid layer is not formed, said active energy-ray-curable resin composition;   (c) curing said active energy-ray-curable resin composition by exposure to an active energy ray; and   (d) removing the solid layer to form the flow path.